Laser system for efficient cold molecular ion production for the study of quantum coherence and dipolar interactions in a molecular ion trap

Abstract

In the last five years the study of ultracold molecular ions has emerged as a new discipline within atomic physics. It is now clear that a trapped sample of ultracold molecular ions affords many of the benefits of ultracold neutral molecules, while significantly reducing experimental complexity Ð e.g. large trap depths, long trap lifetimes, and efficient detection. Despite the infancy of the field, there is already a clear path to a wide range of important studies, including the investigation of quantum chemistry, which not only has important implications for understanding the formation of interstellar clouds, but will allow for investigation, and possible control, of reactive collisions; precision measurement of molecular transitions, which can be used to very sensitively measure parity violating effects, as well as to constrain the possible variation of the fundamental constants; and the implementation of a scalable quantum computation architecture. Through our ongoing ARO Grant (Efficient cold molecular ion production for the study of quantum coherence and dipolar interactions in a molecular ion trap; W911NF-15-1-0121), we performed a series of experiments aimed at understanding the collisional physics between ultracold neutral atoms and molecular ions. This work resulted in several important observations of cold atomion photochemistry. These studies were among the first of their kind and have helped to open the field of cold atom-ion chemistry, which is shedding new light on chemical processes that play important roles in everything from the composition of the upper atmosphere and the interstellar medium to the operation of explosives. In addition to these reactivity studies, we also developed tools for analyzing trapped molecular ions and recording their spectra, as well as solved several longstanding problems regarding trapped ion Òthermodynamics. Finally, using the results of all of this work, we demonstrated that both the vibrational and translational degrees of freedom of trapped molecular ions are efficiently cooled by sympathetically cooling collisions with laser-cooled atoms. Thus, through our ARO support, we have developed many of the necessary tools and techniques to help open the field of ultracold molecular ion research. However, there is still an unsolved roadblock: we are unable to obtain information on the molecular ion rotational state and thus quantum manipulation of this useful degree of freedom is not possible. While it is very likely our cooling scheme is already producing ground state molecular ions, as detailed in this proposal, it is not possible with the experimental means available to us to verify the molecular ion rotational state. Through this proposed DURIP award, we will purchase a mid-IR laser system that will allow us to probe the molecular ion rotational state distribution. Thus, this award would allow us to study molecular ion rotational sympathetic cooling and probe the coherence of molecular ion rotational states in an ion trap via e.g. rotational state Rabi flopping. With this work, the way to coherent manipulation of molecular ion rotational states will be open.

Document Details

Document Type
DoD Grant Award
Publication Date
Mar 11, 2019
Source ID
W911NF1910146

Entities

People

  • Eric Hudson

Organizations

  • Army Contracting Command
  • United States Army
  • University of California, Los Angeles

Tags

Fields of Study

  • Physics

Readers

  • Molecular Photonics/Laser Physics
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.
  • Systems Analysis and Design

Technology Areas

  • Directed Energy
  • Quantum Computing
  • Space
  • Space - Hall-Effect Thruster